Can solar PV really power the UK?

I am writing this in Tucson, Arizona, under an immense blue sky from which a powerful sun radiates strong energy almost all the year round. Surrounding the city is the Sonora Desert, a biodiversity wilderness full of beautiful cacti and other dryland species. Tucson has huge numbers of very large buildings with surely thousands of acres of combined roof space – and hardly a solar PV array to be seen.

It goes without saying that solar photovoltaics makes a lot of sense here. Solar delivers the most energy right when it’s needed – during the hottest part of the day and the hottest time of the year, when temperatures are consistently over 100F for weeks at a time and everyone has their air-con pumped up to maximum. There is a big role too for solar hot water. Instead, the region’s energy is two-thirds fossil fuels, with 40% supplied by coal power and 27% gas.

This is a place that desperately needs to go solar. The state needs a ramped-up feed-in-tariff to dramatically accelerate PV installations, which few homeowners or businesses can currently afford. PV arrays on rooftops also have the additional benefit of providing shading, further reducing the demand for cooling. However you look at it, solar in Arizona is a win-win-win.

Does the same really go for the UK? I strongly doubt it. Yet solar advocates make a lot of sweeping claims that don’t stand up to serious scrutiny – or even a little bit of basic common sense. Take for example, this statement, in a document on nuclear ‘subsidies’ produced by an anti-nuclear outfit called Energy Fair:

Photovoltaics (PV) could generate about 266 TWh/yr in the UK—about 66% of the UK’s present electricity demand. See “Renewable Energy and Combined Heat and Power Resources in the UK”, Tyndall Centre, 2002.(95) PV is quick and simple to install.

By the way, I regard Energy Fair as little more than a solar industry front group, whose main – though undisclosed – argument with the nuclear industry seems to be competition over who gets the ‘economic rent’ of state subsidies. (I dream of a future where renewables and nuclear advocates work together to get fossil fuels off the grid entirely, thereby avoiding dangerous climate change. But then I’m a hopeless utopian who believes human beings should generally be rational.)

Anyway, let’s look at this claim more closely. 266 TWh/yr is a lot of juice. So it’s time to follow up sources. First let’s go to the source referred to in Energy Fair statement. This is a paper by the Tyndall Centre from 2002, which says the following:

ETSU estimates the practicable resource to be 266 TWh in 2025 (calculated as electricity generated by the application of PV to all surfaces of available domestic and non-domestic buildings, allowing for 10% non-suitable surfaces and 25% shading, ETSU 2000 p.141).

So our realism alarm bells are already beginning to ring. Firstly, this estimate is calculated on the basis of PV applied to ‘all surfaces’ – walls, north-facing roofs and so on, allowing for only 25% shading, which is highly unrealistic as a cursory glance at any building in any location will tell you. Plus, I haven’t seen any wall-mounted PV for a long time. Is it even happening?

Second, this is ‘practicable resource’, which I assume means practicable in a technical-engineering sort of way. It does not mean economic. How much would it cost to install this amount of PV by 2025, given that the UK capacity factor is likely to be about 8% (meaning your hefty capital investment is sitting around idle for 92% of the time)? Note that the Germans, well-off as they may be, are now having to dramatically scale back their own feed-in-tariff due to the long-term cost liabilities now reaching hundreds of billions of euros.

Third, this assessment of the ‘practicable resource’ is not even original to the Tyndall Centre source. Instead, it is merely lifted out of ‘ETSU, 2000’, a bigger study by the now-defunct Energy Technology Support Unit. I can’t find this document anywhere on the web, which is perhaps not surprising as it is more than a decade old. (Let me know if anyone comes across it and I’ll post a link.) Couldn’t Energy Fair come up with anything newer? Or does nothing more recent have a similar and conveniently-large figure? Looks like a classic cherry-pick to me.

Perhaps a better way to more realistically assess the practical UK solar resource would be to use DECC’s energy calculator. Here you can select a very optimistic assumption of 9.5 square metres of solar PV panels per person, with “all suitable roof and facade space used”, by 2050. All this adds up to about 140 TWh/year in terms of generation, but that is still only 25% or so of what is needed given a realistic scenario of electricity demand increase. (Electricity demand will increase even if overall energy use falls due to efficiency; this is largely the result of electrification of transport and heating. The specific scenario selections on the graph are my own.)

[It has also been pointed out to me by David MacKay, after the first iteration of this post, that “the peak capacity for 140 TWh/yr would be
about 140 GW which is far more than midsummer demand – in fact it is
more than any demand ever. So you’d either need to shed solar (or wind or nuclear)
at midday on most sunny days, or you’d need to set up very large capacity energy
stores of some sort.” Worth bearing in mind also in trying to keep things realistic.]

Perhaps a more realistic assumption would be 4 square metres of PV panels per person by 2050, still a major achievement, but delivering only 60 TWh/yr of electricity and a relatively small contributor therefore to overall production. (And one needing a lot of backup, depending on the fuel mix of the rest of the grid.)

What is this telling us? That setting solar up against nuclear is a sure bet to a climate fail. I agree that solar has a role to play even in the cloudy UK, but it is not a big one. It’s great that the solar enthusiasts are working to achieve the end of covering all suitable rooftops, and let’s hope that costs continue to fall sufficiently so that this will one day become an economically-feasible endeavour. But please, solar folks – just focus on doing your own jobs. Stop trying to squeeze other low-carbon generation technologies – like nuclear, which can deliver far more, more reliably, and at lower cost – off the grid at the same time.

108 Comments

Gidon Gerber5 March 2012 at 5:51 am

IMO, it would be much more economical to invest (on a European scale) in power transmissions networks, and import solar electricity (PV or thermal) from places where sunshine is abundant (like Spain, Greece, southern Italy and northern Africa).
Already there are periods when Spain produces more solar electricity than it consumes, but cannot export due to lack of transmission capacity.

I wonder whether it is fair to focus on the area of British roofs. Ground mounted arrays are far cheaper.

Just suppose the UK were to want to generate a lot of power from PV. It would be sensible to cover large areas of low quality pastureland with panels.

What sort of space would be required? To generate 10% of the UK’s current electricity consumption would take ‘an area the size of Wales’. As you sagely point out in other places, to get the same power from nuclear plants you might need cover only 0.1% of the Principality.

One point: “wall-mounted solar” would require planning permission at the domestic level and few houses would have much if any suitable space, but solar facades aren’t unknown, eg two in London on Bishopsgate (one finished, one in the making AFAIK).

Powering western Europe and Great Britain from Spain or even Morocco makes sense. There is so much sunlight there that even with voltage drops in transmission lines there would be sufficient power to meet all reasonably foreseeable needs.

One concern — that PV panels need to cover vast swaths of the desert — has been addressed through good design. Vertical towers surrounded by mirrors that concentrate the sun’s rays onto a fluid that, in turn, heats up and runs a generating turbine, work as well or better than traditional flat solar panels. These systems have the additional advantage that the fluid can be molten salt, which retains its heat at night, providing electricity 24/7.

Britain should develop some solar capacity of its own, of course, for backups and to help control rates. But the idea of buying energy from foreign sources is hardly new, and if the investment is provided by the purchasing countries and the plants are co-owned by them, energy security will be ensured — much more so than it is when, say, buying natural gas
from Russia.

But in the UK there is no equivalent peak in the middle of the day. Demand rises at breakfast time, stays almost flat for the day, and then rises in the late afternoon to peak in early evening.http://news.bbc.co.uk/1/hi/sci/tech/7268832.stm

This means solar in the UK tends to peak at the wrong time. So, unlike Germany, if there was a large amount of solar generation it would just disrupt cheap baseload generation during the day, leading to higher costs rather than saving money.

There still is a big load in the middle of the day on the GB, even if not the very peak (typically two-thirds of peak), so if solar covered much of that minus non-load-following nukes in summer it would be mainly good I suspect.

We should reserve as much biomass/MSW as possible for peaking (ie effectively storage) if such plants can be constructed to load-follow efficiently.

Then only what it and wind (+ other intermittents) don’t cover needs to be picked up by fossils.

Rgds

Damon

ColinG7 March 2012 at 4:48 pm

“There still is a big load in the middle of the day on the GB”

There is a big load, but it is flat.

Look at the two graphs I linked to.

For germany there is a clear correlation between the solar peak generation, and the peaking electricity demand around mid-day. Therefore solar dipslaces expensive peaking gas plant. This makes sense even when solar is relatively expensive comapred to baseload, as long as it is cheaper than peaking gas plant.

In contrast, the other link shows a graph for the UK, and there is no mid-day peak in demand. It reaches a high load at 7.30am, stays flat until around 4pm, and the peaks in the early evening.

So if you introduced a large solar supply in the middle of the day, what is going to happen? The baseload plants would have to cut their output to accomodate the extra supply. Or alternatively you would need gas peaking plant at either side of the solar peak, to maintain the flat supply.

Either way, the solar peak in the UK would not be displacing expensive peaking gas plant; it would force cheap baseload plant to change into expensive peaking/load-following operation, to fit around the solar peak. This pushes electricity prices up.

I made a silly mistake in my comment above. Many apologies. My numbers should have shown that UK electricity demand could be met (over the course of a year) by an area a tenth of the size of Wales, not that Wales would generate 10% of UK demand.

It may be worth mentioning that the cost of solar farms is now down to about £7m for a 5MW installation. Anybody with access to low cost sources of funding can now just about make the numbers work, even at today’s sharply reduced feed in tariffs. Whatever else we might say about PV, it is delivering very sharp cost reductions: down by nearly 50% in a year.

Is it accurate to say that “UK electricity demand could be met (over the course of a year) by an area a tenth of the size of Wales.”?

I am aware that there is some promising work on improving the effectiveness of solar panels at night, but is it currently possible for solar to power night time electricity demand?

Cyril R7 March 2012 at 12:30 pm

The question with solar is not what do the installations cost. The question is how do you power the country with solar if you don’t want to use fossil fuels. You can use energy storage but if you do any calculations on even a week of energy storage (not enough) you will find prohibitive costs. Moreover, there are no developments, not even in the lab right now, that will produce much cheaper energy storage than today’s technologies (eg deep cycle lead acid).

So the risk with cheaper solar is that we all install the things on our roofs, feeling mighty fine about the effort, only to find out that we need to burn fossil fuel most of the time – the sun is not there on average, 90% of the time in the UK, technically speaking (10% capacity factor). Then we will wake up to find ourselves addicted even further to Russian and Lybian natural gas, and insufficient greenhouse gas reductions (we need 80% before 2050).

Considering the lack of cost developments in energy storage, this risk is very real.

J Bowers17 February 2013 at 9:11 am

“the sun is not there on average, 90% of the time in the UK, technically speaking (10% capacity factor).”

A University of Sheffield two year study has found that UK weather reduces PV efficiency by a paltry 2%. It’s thought that the photons are scattered more and the panels are catching more photons through the day, making the panels less reliant on orientation.

Cyril R7 March 2012 at 12:23 pm

266 TWh/year, a number that is easily bandied about. Let’s dive deeper into this number.

On a sunny day you will produce too much power at noon (and still almost nothing at night, late evening, early morning, and in deep winter). So you have to dump all this power throughout all summer noons – just when PV delivers the most you can’t sell the power!!!

And this is being generous; covering all available areas means not having optimally inclined south facing installations. You won’t get 10% capacity factor on a wall mounted panel, even a south wall mounted panel, in the UK climate. It is likely that more like 400 GW of peak solar installed capacity will be required to get to the 266 TWh/year.

Worse, the UK’s peak electricity demand occcurs in winter, when it is cold and dark. Typically in the winter days you get 1-2% daily capacity factor. So your 400 GW of solar panels only makes an average of 4-8 GWs, when your demand is the highest.

With heat pumps catching on this will become even more pronounced. Thus, PV generates at a profile that is opposed to what the UK needs. This profile is related to physics; there’s just less sun in the winter. The poor sexy solar panels can’t be faulted; it is their resource that fails the UK.

here’s a website that looks at the total PV output of Germany, which has a roughly the same solar output (climate) as the UK:

You have reported the quote perfectly accurately but completely out of context. It is not a recommendation of the report, but is one in a list of 7 bullet points illustrating there is plenty of renewable resource theoretically available.

In fact (and this is very back of envelope) if you did everything they suggested you’d generate almost 15 times more energy than you need (7x by wind, 6x tidal etc, 1x desert based concentrating solar, 0.6x PV). Perhaps that is why they say “there are several reasons why Europe and the UK (and other regions and countries) should use a variety of renewable sources of power”.

I think it is perfectly fair to query whether this is a useful way to illustrate the potential of renewables or not. Personally I’d say it is a bit like saying we can pay off the deficit by putting £234,632 tax on every packet of fags – possibly true* but not actually very helpful. But to present the claim as if it were a policy proposal – when the document says it is not – is misleading.

I’m also interested in this “solar front group” thing again. I clicked the link you provided which showed Dr Fouquet and Dr Wolff’s links to the reneable energy groups they are part of in the “about us” section. If they are undercover operatives, they are not very good at it.

And as I have said before – I think a bit of healthy competition between the various technologies for the taxpayers money we need to spend to develop low carbon energy is a good thing. Not entirely sure why you don’t – particularly as despite being a self proclaimed utopian, you are knocking one techonology just as they do.

*I say possibly true, but it would be remarkable if it was, as I made the figure up. Hopefully illustrates my point though.

Saying that there is enough renewable resource without looking at when that resource is available, now THAT is losing all context!

Countries don’t want their power delivered on average over a year. Indeed, a one minute mismatch is considered a national scandal. Electricity is the beating hart of advanced societies, because its high exergy allows us to complex and advance our society in ways that are not feasible with primitive energy sources such as heat. Electricity needs to be there every second, every minute, every hour, every day, every month, every year, yes sir every year in the decade. If you overproduce then your solar panels spill their energy. If you don’t produce, you must burn natural gas. That’s during night, evening, morning, winter, cloudy periods, rain, and snow. Oops that most of the time in the UK!

We can, at great cost, cover all roofs with solar panels.

What the pundits don’t say with that marvellous fact, is that you can’t power your countries with it. There aren’t enough rooftops, but that’s not the most important problem. The energy is simply not there 90% of the time, and cannot be turned on when needed.

Sexy solar panels can’t be blamed. The sun itself is inherently unreliable. In winter, it goes away with the daisies and doesn’t come back until they do.

martyn7 March 2012 at 6:17 pm

We buy many things that don’t work all the time. No one suggests my bike is pointless because sometimes I need to use my car. And no one complains when the shiny new 150 bhp car they bought spends 99% of its time producing no horsepower at all because it is parked on their drive.

Our energy demand is also not immoveable or unchangeable. Many products could match their demand to supply more – fridges, air conditioners, electric heating, battery charging could all become sources of dynamic demand because there are many points in their work cycle.

So yes, I agree we have to look at when a resource is available. And we have to have regard to the cost. And (as the paper Mark quoted said in that part he didn’t quote) we need a variety of sources. But none of that stops solar playing a useful role.

Mark Lynas(Post author)7 March 2012 at 6:20 pm

Indeed Martyn. But here’s a question for you: do the factors you just listed stop nuclear playing a useful role?

And I’m not “knocking one technology” – didn’t I start the piece by pleading for more solar PV in Arizona, where it is very sunny, and demand matches supply much more?

martyn7 March 2012 at 7:02 pm

No, none of the reasons I have given in that comment are factors that stop nuclear playing a role. I think there are other factors that are more likely to stop it – but time will tell.

And you are knocking PV’s role in UK – you say that you “strongly doubt” the UK should have the policies you prescribe for Arizona of a FIT that encourages many homeowners to install solar.

But consider this – average insolation (i.e. the amount of solar energy) in Arizona is about 4.5 kWh/sq m/day. In UK it is more like 2.5 kWh/sq m/day – i.e. we get a bit less than half the energy, and so would need almost twice as many panels for the same power.

So if it makes a massive amount of sense in Arizona now, then once panel costs halve, it presumably makes a massive amount of sense in the UK too. (In fact it would be before then, because panels are only part of the cost of a solar system, and the we get slighly more than half the energy they do).

I can’t tell you when panel prices will halve in cost again – that is crystal ball stuff. But had you written this twelve months ago, we would be there now. And I don’t see many people arguing that substantial reductions in the cost of solar are now a thing of the past – that we’ve reached the bottom.

Ultimately that is what I think will stop (much) nuclear power being built. It cannot boast falls in price like this – and while I am in favour of research into more efficient ways of generating electricty from nuclear power, and interested in the clean-up role that might be played by some new designs, I don’t see any of that happening as quickly as we need it to. But as I said….time will tell.

cyril r7 March 2012 at 7:17 pm

Martin, you didn’t get my analogue. Your car may be parked 99% of the time, but when you need it, you expect it to work. That 1% of the time that you do use it, is by your chosing, and it must be ready. It must be dependable.

You are comparing two different things here; capacity utilization and dependability With solar, both are exceptionally poor. With a car, most people only care about one of them being good: dependability.

It’s vital that you understand the difference.

martyn7 March 2012 at 7:24 pm

sorry typo in above comment – we get a bit *more* than half the energy of Arizona, not a bit less. It’s about 55%.

The UK numbers sound higher than I would expect from the data I have seen, but I am only inferring this and have never seen direct comparisons.

cyril r7 March 2012 at 5:52 pm

Here’s a nice analogue to consider the problem of solar power.

Imagine you are going to buy a car to drive to work 5 days in the week. The car dealer asks you how many miles you drive each year. You say, 10000 miles. The car dealer sells you a car which is guaranteed to drive 10000 miles.

You think you’ve got a pretty good guarantee. But when you want to drive to your work, you find out the problem with this car: it only starts once every week! You can’t use it the other 4 days. Also, sometimes it doesn’t start for months, and then it does start 4 times a week. You go back to the dealer. The dealer refuses to give your money back; after all, the car would do 10000 miles a year, and that’s what the dealer guarantees.

We can all agree this isn’t a useful car, and the dealer has screwed you over.

How come we don’t see this with solar panels? It’s a remarkably similar story.

I’m sorry, but it is a ridiculous analogy. Solar PV connected to the grid is part of a system. Of course, because it has particular charateristics, we have to ensure that this system can accomodate it, but no one is suggesting the entire country go 100% solar without any backup, storage etc.

Accomodating particular charateristics of generation is not unique to solar. Nuclear is hard to turn off (part the reason “economy seven” was invented to stimulate demand for electricty in the night), coal can’t turn up and down very quickly in the ad breaks in Coronation Street. Different accomdatioon is needed depending on scale too – if one large station shuts down for maintenance/because of a fault, that’s potentially a big loss to the system – having more smaller plants are less likely to involve such a major outage. None of these problems are insurmountable – but stop pretending it is only solar that has charateristics that the system needs to accomodate.

I do not want to be massively anti-nuclear about this because it really isn’t the point – but would you think I had a good nuclear analogy if I said you had gone to a dealer and bought a car only to find it had to be left running the whole time, even when you were not using it?

Mark Lynas(Post author)7 March 2012 at 7:24 pm

Martyn – your analogy on nuclear isn’t all that bad! And I’m happy that you are interested in the potential for waste recycling and clean power generation in 4th Gen reactors – that puts you a step ahead of many.

My argument for nukes is (in the UK context) primarily to displace coal from baseload production. In terms of grid balancing, that is a complicated issue, which many pronounce on with a minimum of understanding. It is often used as an argument against wind, which I think is largely bogus.

I think grounding this debate in the DECC calculator is quite a good discipline, which I know we’re both happy to do.

cyril r7 March 2012 at 7:47 pm

It’s a pretty poor analogue, considering nuclear power as it is today derived from nuclear submarine technology – flexible things where throttling and reliability are paramount.

Nuclear plants can tune down just fine. Especially BWRs are good at it, just tune down the recirculation pumps and you can load follow as quickly as any steam turbine can.

But what is the point? We need power most of the time, and nuclear delivers it cleanly and at low cost. If you had a money machine that costs 10x less to operate as it earned you, would you consider shutting it down? A large nuclear plant like an EPR can make over 800 million pounds a year. That’s more than 2 million pounds a day. Why shut that down?

The historic fact is that France gets 80% of its power from nuclear. This is not a projection, or crystal ball gazing cost developments, this is real right now. France can do this because they shut down plants over the weekend and in the low demand season (summer), and because most demand is baseload anyway.

cyril r7 March 2012 at 7:34 pm

Martin, in your analogue of the car that must run all the time – no this is a bad analogue. Nuclear plants can be shut down easily. France does it effectively, closing some plants over the weekend. They get 80% of their electricity from nuclear and 10% from hydro. That’s a 90% carbon free (well nearly) solution.

If you are a taxi driver, you would like a car that can run a lot. You can shut down the car if you want to, but that’s silly because you need it to make your money.

The truth is, if you look at some electric demand profiles, they are surprisingly steady – much much closer to a nuclear plant output than to solar. And you can turn on these plants when you need them.

cyril r7 March 2012 at 7:41 pm

“solar PV is part of a system”

If you have a component which delivers only 10% of the time, but need power, say 60-70% of the time, what do you think has to happen in the system?

You use something reliable, flexible, and dependable to cover up the component poor performance. You build a natural gas turbine and run it when the component isn’t working well, which is most of the time.

I want to transition away from fossil fuels, not lock ourselves in them.

martyn7 March 2012 at 7:21 pm

@cyril

I see our replies crossed in the ether. I do understand the difference, but once you find me someone who recommends the UK go 100% solar powered I’ll consider your argument worth addressing. In the meantime it is no more than a straw man you have set up.

PS – Martyn, what is the source for your ‘average insolation’ figure? Does it account for the usually blue skies in Arizona, versus the more cloudy climes of the UK? I’m concerned it may just be about latitude and day-length.

they come from the NASA site and to answer your questions I checked the figures more carefully there. You’ll have to follow the link as you need to register to use the tables so I can’t simply send you a link.

However, I used Lat 51, Long 0 for London and 32, 94 for Arizona. Figures are at the surface 4.76 kWh/sq m/day in Arizona and 2.82 in London. At the top of atmosphere the figures are 8.6 kWh/sq m/day in ARizona and 6.68 in London.

So I am pretty confident that my half as much is just about right for a panel in use.

cyril r7 March 2012 at 7:29 pm

You can never do just one thing Martin. If the UK goes on with a large solar build, then you’ve introduced so much variation in the system, you’ve locked yourself into natural gas effectively, for the life of the solar installations (which is decades). Energy storage is too costly (batteries) or can’t scale (optimal location pumped hydro).

If we want to phase out fossil fuels we need a plan that adds up. The way you put down your argument is “no on is proposing to solve the problem 100%” so “it is a straw man argument”. Don’t you see what you’re doing here? You’re saying, let’s not solve the problem 100%, and be happy about it. Your putting up a loser loser situation. Solar can’t power the country, but we won’t power the country with it in the first place. Heads I lose, tails you win.

This is not acceptable to me; we need to cut CO2 emissions 80% before 2050, in a growing world economy. That’s such a deep reduction, the best way to think of it is: no more fossil fuels.

So yes we do need to plan for this. Not planning for it is a sure shot for failure.

So our choice is between running a bit of solar and a lot of natural gas (or worse, coal), or little solar and lots of nuclear, but little natural gas (and certainly no coal since these are baseload things).

martyn7 March 2012 at 9:06 pm

Cyril – you cannot make an analogy (and it is an analogy, not an analogue!) with a car and then say you were talking about a system all along. Cars are standalone, powered by just one thing (at least if we exclude plug-in hybrids for now).

However, I am glad you have accepted it is a system we need to talk about, but sorry your examples are so incredibly limited and frustrated at their contradictions.

You say new nuclear can turn on and off easily – but say we must have gas as a balance for solar. You say because solar is not operating all the time it is not economic – but then say we can turn nuclear power stations off for weekends and in summer. And your examples of our options for systems completely ignore wind, tidal, geothermal and hydro generation. You also ignore the dynamic demand technologies, European interconnectors and other demand-side innovations we could use to help deal with intermittency.

I agree with Mark, the DECC calculator is a useful basis for this debate – and one of the most striking things about it is the multiplicity of ways we could achieve our 80% cut – I know Mark would agree you can do it with or without nuclear, and I would agree we can do it with or without solar.

Ultimately we need to end up with a system that keeps costs relatively low, and is publically acceptable. I have no problem in principle with paying extra for two wind turbines to be located out of sight in a valley rather than one on a windier hill if people are happier that way. Many people will pay extra for a house with a nice view, and I can’t see the difference.

I also have no problem with people deciding they are happier without the risks nuclear poses even if it was one day uncontestably proven to be cheaper. That may raise hackles – but I can’t see why it is different to feeling happier when your belongings are insured or have extended warranties, despite the fact that you’ll probably be worse off insuring things because premiums cover the costs of losses and administration and profit etc.

This is complicated and I can’t see your posts are getting anywhere near it.

cyril r7 March 2012 at 9:50 pm

The prime contradiction you can’t seem to understand is between capacity utilization and dependability. Even if a car is used only 1% of the time, you want it to be 100% available within that narrow 1% usage band. Solar is the opposite; it’s not available when you want it, just when the sun shines, which is technically on average not the case 90% of the time in the UK.

You are trying to bring the debate into a good analogy bad analogy debate. This is a diversion tactic. The key question framed by Mark Lynas is, can we power the UK with solar panels. The answer is no because they are not available most of the time. In particular they are not there in the winter, just when the UK needs most power (dark and cold).

Wind is completely random, jerking up and down also because of fundamental resource problems – wind power goes as the cube of wind speed which makes wind power unreliable.

You cannot hide in some complex system of unreliables, wind solar and such and claim to power the country with these things. These analysis have been done and it doesn’t work. But a simple comparison of the wind production profile in winter, when there is little sun, is all telling. There are many weeks and days of very low wind output. Again if you install too much wind you have overcapacity at some times and undercapacity at others. This doesn’t work. You cannot power the country with stacking unreliable non-dispatchable power sources on top of each other. The reverse is true: the more unreliables you add to a system, the more flexible gas turbines you must have running. I’m sorry that this is the case, but it is true.

There is really too much for me to say. Geothermal is too limited as is hydroelectric – please read David Mackay’s Sustainable Energy – Without the hot air. You’ll see what I mean pretty quick.

So we are left with a decision. We cannot do just one thing. Solar and wind means going natural gas for the UK. Whereas nuclear promises to be that 80+ percent solution.

All the demand side regulation tech you mention works much better with nuclear power. For example plugin hybrids can charge off peak with excess nighttime nuclear capacity. They cannot charge from the sun which is not there in winter or the wind which has its own mind. Sometimes the wind has a mind to not deliver much power for weeks. You can’t charge plugin hybrids form this. You need a reliable source once again, to reliably charge everyday commuters plugin hybrids. All the demand side tech is useful for interday regulation, not much more. It won’t make the sun shine in winter. It won’t make the wind blow in a week calm spell (and if that occurs in winter, it’s power down the country or burn natural gas). Pumped hydro energy storage is good for hours, not seasons.

The DECC calculator makes the exact same mistake that it barely matters when the energy is delivered. In fact this is crucial. You can’t simply assume things like 266 TWh/year when looking at when you are producing how much. Having 400 GW of solar panels in a country that needs no more than 60-70 GW ever, is not going to work. But it takes a bit more looking beyond the kWhs and the TWhs to see this.

It is true that it is complicated but simply making catchphrases that “it is complicated” so we must be able to power the country with wind solar geothermal and whatnot, is a non-sequitur. The burden of proof lies on you renewables enthusiasts to show that we really can do these things. I encourage you to look at the real numbers and what we really need and what solar and wind really deliver. It doesn’t take a scientist to compare these things and get a general feel of the challenge that renewably powered UK faces.

martyn7 March 2012 at 10:23 pm

I have repeatedly answered the question at the head if this column.I have said that powering the UK with 100% solar is plainly daft – every answer I have posted has said so. Furthermore I began by saying I don’t think Mark needed to ask the question because the report he referenced specifically called for a mix of generation.

Robert Wilson7 March 2012 at 10:34 pm

I think Mark’s question was perfectly valid, as it was directed at the statistics used in the Energy Fair report, where they claim solar PV could provide 66% of the UK’s electricity needs.

You have criticized Mark for taking Tyndall numbers out of context, when it is in fact Energy Fair who are doing so.

cyril r7 March 2012 at 7:23 pm

Oh and by the way: solar doesn’t make a “massive amount of sense in Arizona”. Solar panels in Arizona don’t produce power 80% of the time, on average, and it can’t be turned on when it isn’t there – its not dependable. The correlation between peak electric demand and solar output also is not very good: peak electric demand occurs later in the day than the solar peak, which is at noon. Here’s an example of this for California:

Also there are hazy hot days when you have less solar output but still a lot of airconditioning needed.

That said I can see a fairly optimal system in which PV systems make ice or chilled water (energy storage built in) to power airconditioning, and remote terrestrial powering, and nuclear as baseload to power most other things such as industries. This would be a mostly nuclear grid with solar PV to deal with most peaking so the remaining demand is mostly baseload.

UK electricity demand is quite steady, closest to baseload. So the UK can do what France did and mostly solve the problem by powering the country on nuclear, in stead of trying to do cool sexy things that don’t work (and will get us more fossil fuels)

Robert – I saw a map today with tiny squares on it showing how much of the worlds surface we need to supply the worlds energy supply. It is not a policy proposal, but an illustration.

Likewise, Energy Fair listed numerous theoretical sources of UK energy. It is probably the least daft one if we have to take one as a policy proposal – others suggest building 6 and 7 times as much capacity as we need.

They specifically say that a mix of generation is needed. How they use Tyndall figures is irrelevant to Mark using his headline a question whether something no one has proposed is possible. Even if Energy Fair were proposing this as a policy (which clearly they are not) they would only be powering 2/3rds of the UK with solar.

The strange dichotomy of solar power is that, yes, the sun provides thousands of times more energy than we need anually. And no, it doesn’t deliver it when we need it. That’s something few solar enthusiasts see; the problem with solar is when the energy is delivered, not how much land we’d need. In case of the UK it needs most energy in winter, when the sun produces little power, a few percent of capacity. Basically the sun comes and goes with the daisies. You can overbuild the solar fleet, at great cost, but you still don’t have enough power for winter and you have to dump most energy in the summer at noon – just when you’re producing the most.

Solar is not good for powering countries. Trying to do this will end up in big natural gas lock-in. Solar is good for a few specialized uses such as remote powering, airconditioning in hot climates, etc. Nuclear is good for powering the rest of the country.

Robert Wilson7 March 2012 at 11:06 pm

Martin

I think you are being inaccurate in your presentation of what Energy Fair is saying. They are claiming that the UK could realistically get 66% of its electricity from solar PV.

Mark’s point is that this is highly unrealistic and that basing opposition to nuclear on this assumption is a bad idea. Unrealistic numbers like these are thrown around by environmentalists all the time. Do you not agree that it is valid to criticize them?

Can you also please provide a source for those Arizona solar insolations? The UK numbers look OK. I have googled and found numbers for Arizona and they are all above 5.5, not 4.5. I will try to check these numbers from the NASA source data tomorrow,

I have given sources – look higher up. Maybe we will have to agree to disagree on our interpretation of Energy Fair, but could you at least explain why you think they are saying this bullet point is sensible, whereas the other 5 or 6 bullet points don’t seem to be a problem?

If someone offers 6 or 7 “options” that add up to about 15x more power than the UK needs it seems fairly obvious that they are not proposing all are implemented. And when they say a mix makes sense it becomes even clearer.

This should have been mentioned – from Mark’s quotes it appears to be a policy proposal for 66% solar, which in context it clearly is not.

I don’t believe Mark was suggesting that Energy Fair wanted a 66% solar target. The criticism is that they claimed the UK could aim for 66%, which if you look it the numbers is highly unrealistic.

You can seek clarification from Mark, but I only read what he wrote as a criticism of optimistic forecast of renewables Energy Fair gave.

The headline as far as I can tell is not specifically related to Energy Fair’s claim, but if you were to ask a random selection of environmentalists a surprising number may in fact believe the UK can be ‘powered by solar’.

I posted the links in response to Mark’s request earlier. I think Mark has to approve posts with links, so probably that is why they are not there yet. No point posting again as the same will happen – but the basis was NASA figures.

On the substance, could you provide a link to an environment group or even solar salesman proposing 100% as a policy? If you can’t then your statement about a random selection of environmentalists views is about as helpful as me saying a random selection of nuclear enthusiasts think radiation is good for you.

As it happens, I’m prepared to say the UK could go for 100% solar if it had to (if fossil fuels and all useful radio-isotopes ran out, tides and wind stopped etc). We have sufficient space for the panels, and would have to dramatically change when and how we use energy, and it would be very expensive but we could do it if we had to and there were no alternatives.

But extrapolating that statement to saying I have given an overoptimistic indication of what solar can deliver would be madness.

And let’s be very clear – Mark has so far fallen short of proving the 266 TWH is not theoretically possible. He managed more than half of it with roofs and facades. Add in solar farms, and some redesigning of buildings (roof remodelling). I’m not proposing any of this .. but nor were Energy Fair.

Chris Goodall has his own calculation up the page to – 10% of wales generates 100% of UK power he says. Should the Welsh mobilise to keep him out, or is it an illustration?

Can you put these two together? You’ll be dumping solar all the noons in summer (and still have no power at night and too little in winter).

martyn8 March 2012 at 12:34 am

Oops – cock up confession. Arizona insolation is 5.4 kwh/sq m/day. Apologies I got my US state abbreviations muddled and read the Arkansas (AR) line instead of Arizona (AZ). When Mark approves the post with links, the same error will apply to lat and long I used – they will put you in Arkansas.

It is still roughly half though – admittedly just under now rather than over.

Apologies for error and thanks for checking Robert. You may find the tables and links to NASA data if you add apricus to a google search for insolation levels.

When did I say people were proposing that the UK should go 100% solar?

I said a significant number believe we can get 100% solar.

In terms of people claiming it is realistic, well it feels as if Jeremy Leggett claims it every day.

I really wish you would stop going on about this ‘proposing’ business. Neither Mark nor I are criticizing people for what they are proposing, but what they are saying is realistic.

You appear to be agreeing that getting 266 twh from solar is a push, which is precisely Mark’s point. The argument of Energy Fair is that if we can get this from solar then we don’t need nuclear. Whereas I, and I guess Mark, would argue that there is a lot of uncertainty in the eventual solar roll out, so we shouldn’t simply consider best case scenarios. It may be 266, but it may also be 60 TWh. Many of the 100% renewables scenarios are sitting right on the edge, and the difference between 266 and 60 TWh may be the difference between the UK meeting or failing to meet it’s emissions targets.

“When did I say people were proposing that the UK should go 100% solar?
I said a significant number believe we can get 100% solar.”

Lets go back to the beginning.

Mark’s headline question is

“Can solar PV really power the UK?”

We ought to be completely clear what that means – if “powered by solar” means the UK can take *some* power from solar then it would be a meaningless question, since we know it already is (I’ve seen the panels on my roof). So it must mean 100% powered by solar.

I said this was a daft question because no one was advocating it. You responded

“I think Mark’s question was perfectly valid”

for various reasons, including that

“if you were to ask a random selection of environmentalists a surprising number may in fact believe the UK can be ‘powered by solar’”

Now you didn’t make it clear whether this group of people you made up thought it was only theoretically possible to power the UK with 100% solar, or whether they thought that it was a serious policy option. As the former doesn’t breach any of the laws of physics – I would contend it is true. But of course,you wouldn’t do it except in ludicrously extreme circumstances which is why I repeatedly have said we need mixed generation.

So either you contend this made-up selection of environmentalists believe something that is theoretically true but practically ridiculous, or they believe something practically ridiculous should be our aim. Your whole tone is highly critical of them, which rather implies that you believe they want to do something daft – like power the UK 100% with solar.

There is a massive difference between “saying” something and “proposing” something and I am sticking to it for a very good reason. I can “say” that the world recieves as much energy from the sun in just hour as mankind uses in a year. That is true – but it does not mean I am “proposing” catching all that energy and using it for the year. Using both words enables me to illustrate something without being committed to carrying it out as a policy. Rather than getting upset with me for being clear, perhaps you could start making the distinction too so I don’t have to go through long inferences to understand what you think imaginary people think.

And I’m sorry, but your Jeremy Leggett point is utterly ridiculous.

Has he said 100% solar is realistic or not? I don’t care what it feels like he has said – I care what he has said. I don’t care if you find him irritating or not either really – that’s not actually the most important thing going on here.

So when Energy Fair say it is possible to get 266TWh a year, you must either prove them wrong – by showing this is not possible, or you must find them proposing it as a policy. If you could do this, I would agree with you that there are much better policies.

However, you can’t do the first (because it is possible) and in my opinion that you can’t do the second either – because you would have to either have to explain why they propose their solar bullet point as policy, but not the other 5 or 6 bullets. Or you would have to explain why they propose all the bullet points as policy, despite the fact we would then generate far more energy than we need.

What I accept Energy Fair did do is to leave out some of the provisos on how hard it is to reach 266TWh. It would have been better if they had. But then they also don’t put any explanation on how hard the other bullet points would be either – and they include

“A network of land-based 2.5-megawatt (MW) turbines restricted to nonforested, ice-free, nonurban areas operating at as little as 20% of their rated capacity could supply more than 40 times current worldwide consumption of electricity and more than 5 times total global use of energy in all forms. There is additional potential in offshore wind farms”

To be honest that makes 100% solar in the UK look a piece of piss.

So I am at a bit of a loss as to why you and Mark are hung up on this particular bullet point, unless this is it the start of a series of columns criticising them all in turn. Or we could apply some common sense…

Finally, you say

“The argument of Energy Fair is that if we can get this from solar then we don’t need nuclear.”

I don’t think that is the main point they are making by a long way.
Their report is not anti-nuclear because of 66% solar being available. It is anti-nuclear because there is a lot of renewables available – far more than we need is their contention, which is why they can then able to pick and choose which things to use. So why get so worked up about their claim of 66% capacity coming from solar when they are claiming 4000% of it could come from onshore wind?

Robert Wilson8 March 2012 at 4:02 am

My point about Jeremy Leggett is not ridiculous. He has said on more than one occasion that PV panels on roof spaces would provide all of the UK’s electricity needs.

I have not read the wind paper referenced, but will do so. However, as far as I know getting 4,000% of the UK’s electricity needs from onshore wind is arithmetically impossible if you use an assumption of 2 watts per square metre.

I can’t speak for Mark, but clearly the purpose of this article is not to give a full critique of Energy Fair, but to use their claim about solar as an example of hugely optimistic figures for solar.

I still fail to understand why you keep going on about people ‘proposing’ things. You are asking us to explain why we think they are proposing all bullet points when this has never been suggested.

The problem here is that Energy Fair is throwing around the biggest figures they can find to make nuclear look unnecessary. Surely it would better for realistic projections to be used instead of the biggest figures a couple of activists could find.

Robert Wilson8 March 2012 at 4:56 am

Martin

I have quickly read the PNAS paper referenced by Energy Fair. The result in the paper is for potential wind energy, I.e. they imagined wind farms on all land, except that covered by ice, forested or urban, and then calculated the resulting wind energy. Clearly getting anywhere near the amount of energy quoted in the paper is ‘a piece of piss’.

In the paper UK estimated potential onshore wind potential is slightly over 10 times the current electricity demand. Now, clearly you cannot put wind turbines on all potential land.

I am not entirely sure if the authors of the report read the PNAS paper and did not understand it or if they did understand it but simply assumed they could quote mine from it and get away with it.

Do you believe these numbers are a rational basis to base energy policy on?

Robert Wilson8 March 2012 at 4:57 am

Typo – not a ‘piece of piss’

martyn8 March 2012 at 9:36 am

That’s the way to go Robert…don’t answer any of the arguments put in my post, don’t address the inherent lack of logic in your own position, or my initial complaint that (a) Mark did not quote the relevant bullet point in context and (b) asked a headline question about a whether a scenario no one was claiming was possible is in fact possible. You of course though (b) was “perfectly valid”.

Also skip over the fact you have failed to find an environmentalist who has called for 100% solar – so instead have used as evidence (a) that it “feels like” a solar advocate you don’t appear to like much says it every day and (b) invented a group of environmentalists in your head and predicted they may say it.

No, clearly dealing with all that is too difficult, so instead start a new complaint and pose a “killer question”. No matter that this is as as fatuous as the last one – or that you had to rely on me to lead you by the nose to the new bullet point when I was illustrating how you misinterpreted the previous one.

But despite the fact we leave all that hanging and unanswered, let me address your latest post:

I now think you owe the authors of the Energy Fair report an apology for writing

“I am not entirely sure if the authors of the report read the PNAS paper and did not understand it or if they did understand it but simply assumed they could quote mine from it”

I’m pretty confident they did read it because they quoted it virtually word for word. That would have been quite a coincidence had they not read it. As for understanding it – well they chose almost the identical words to the ones you chose to describe how the figure was arrived at in their paper. So presumably they came to a very similar understanding to you as to what the paper was about. Finally to allege “quote mining” – well, as they quoted the same words as you did, so you have either both misled us through quote mining, or neither of you have.

You have made a serious allegation on the basis of evidence that doesn’t withstand a moment’s analysis and you should withdraw it and apologise.

And to answer your question – yes I do think it is perfectly rational to assess potential for renewables when considering an energy strategy. I am surprised you imply it is not.

martyn8 March 2012 at 11:59 am

Robert

I apologise – I have been unfair in the above post. I have now read your post of 4.02am with the links to Jeremy Leggett and so on – so it was not fair to say you completely ignored all those points. I suspect it was held ujp in moderation because of the inclusion of links so I only saw your second post of 4.56am.

The fact you have included a link now does not alter the fact that the earlier post saying “it feels like” someone says something is ridiculous though.

As for the link itself – Jeremy calls it an “impressive calculation”, he does not say we should do it. So do you think the calculation is wrong? Given Mark quotes all surfaces could do 66% from a paper dated 2000, and panels have roughly increased their efficiency substantially since they are in the same ball park.

People use all sorts of impressive calculations to illustrate complexity. Nuclear submarines have enough power to power a small city. There is enough cable in a city trading floor to reach the moon. They are not proposals but illustrations. By all means argue they are not useful – I actually started by saying that right at the beginning – but do not quote them out of context as proposals for a policy – which is what this article does in its headline question – a question you said was valid.

Still no one has shows that – as a theoretical thought experiment – the Energy Fair figure is wrong. And still no one has shown they are suggesting we actually do this.

In principle this is what Professor Mackay does to come up with a figure of 50 kWh per person per day in his book as a theoretical solar yield. He makes the calculation, and adds in the caveats that make it impractical. I won’t link or this post will be held up too – but it is page 41 of the html version.

I accept that Energy Fair do not dwell on the caveats (though as they are open about what 266Twh means in terms of coverage, most people would immediately recognise is a pretty serious blockage) but they do propose alternatives in other bullet points, making it obvious they do not expect the 266TWh to be generated by solar, but that we have options.

I have said before the criticism is not with what people are proposing, but with what they say is possible. You have constantly asked us to show that they are proposing one of these strategies. Please show when either of us claimed they were.

Energy Fair are saying there is potentially 4,000% of our electricity demand available from onshore wind. This is a number that is in the report simply to impress by its size. Also, the report is aimed directly at the UK electricity market, so why did they choose a global figure, not the UK one, which is 4 times lower? (note: I have no problem with the original paper, it appears to be a good piece of work and has been cited a reasonable number of times). A back of the envelope calculation will show that we need to cover maybe 2.5% of the non-urban etc. land mentioned in the study if we wanted to get 100% of our global electricity needs from onshore wind. (some uncertaintity either way in that 2.5% of course). This also is only current electricity needs, and if we want to double electricity we quickly move up to maybe 5% of available land. This to me is a more realistic picture of the prospects of onshore wind to the one painted by Energy Fair.

I don’t believe it is a good idea to look at the Energy Fair numbers as a “theoretical thought experiment.” The gist of their bullet points is “we have a hell of a lot more renewable energy than we need, so can do without nuclear.” I don’t think we should use theoretical maximums, as they appear to be doing here for onshore wind and solar. As I have shown their numbers for onshore wind quickly go from it producing 1,000% of our electricity to less than 100% once you put any kind of realistic assumption for land covered by wind farms. Putting a reality check on their numbers turn them from “far more renewables than needed” to “just squeezing by with renewables.” Even the most optimistic recent forecast of renewables by WWF made it clear there were not far more renewables than needed.

As for Jeremy Leggett, I am happy to say I find him annoying, and a great deal of what he says, such as solar reaching grid parity in the UK by 2013, feel like nothing more than the output of a solar marketing agency.

My late postings are a result of insomnia and excessive coffee drinking.

Robert Wilson8 March 2012 at 12:59 am

Thanks. That seems to fit with what I was reading. I will probably crunch the NASA numbers tomorrow anyway as I had meant to do this after reading David Mackay’s Sustainable Energy Without the Hot Air, but never got around to it.

Of course we haven’t discussed the fact that peak demand and supply is in the summer in Arizona, but peak demand in the winter in the UK, so I am not convinced solar insolation tells the whole story.

Wikipedia has a page that lists world solar stations 25 MW or larger. Some stations indicate capacity factor. The German stations show a capacity factor of only 11%-12%. That is pretty poor. Since the UK is about the same latitude, I would expect any solar installed there would have about the same.http://en.wikipedia.org/wiki/List_of_photovoltaic_power_stations

You are not telling anyone anything especially new there – I don’t think many people engaged in this debate are not aware that solar generates more power nearer the equator and therefore will be more cost competitive there. But not everyone lives there – and the relevant question is not “would it work better somewhere else” but “is it still economically sensible to use it here?”

If we follow the logic of the “things are not so good at those latitudes” argument into other ways in which we use energy, we’d end up proposing that everyone move out of Scandinavia, because heating homes in cold places takes a lot of energy compared to heating them in sunnier climes (we’d say the same for very hot places too because of the cooling load). But that isn’t very practical, so lets find the best way to deal with providing the energy people need in the places they need it.

martyn8 March 2012 at 5:19 pm

@robert

I still do not understand why it is OK for David Mackay to start with theoretical maximums, but not energy fair or Jeremy Leggett. Your approval seems based on whether authors agree with you or not, which is not a very open minded way of looking at things.

Energy First may start with maximums, but the greater problem is that they finish with them. They quote a number for wind energy which is not even theoretically possible as the PNAS number assumes sticking wind turbines on farms and all kinds of things that likely won’t support them. 4,000% is an impress.

Also I think it is unfair to say David MacKay uses a similar approach to Energy Fair. In the wind chapter he calculates total electricity if all of the UK was covered in wind farms, but then immediately says ‘Let’s be realistic’ and works it out with a very optimistic projection of 10% of the UK being covered in wind farms. I really do not see how David MacKay’s writings on wind are in any way comparable to Energy Fair’s.

I also don’t see why you are accusing me of approving of MacKay and disapproving of Energy Fair because I agree with MacKay. I have set out at length a couple of posts up why I think Energy Fair’s wind figures give an absolutely useless indication of the realistic potential of wind energy.

As I said before there appears to be nothing wrong with the PNAS work (seems to fit with MacKay’s numbers). The fundamental problem I have is that Energy Fair selectively quoted from this paper to make it look as if PNAS had published a paper claiming we could realistically get 4,000% of energy from onshore wind, and this paper claims no such thing. Why did they not put a note in this report making it clear this 4,000% is an impossible figure to achieve?

You are misleading people again. Energy Fair quote the PNAS global figure with the explanation it is global don’t they. And they have a separate bullet on UK figures don’t they? Or have you not read it?

Robert Wilson8 March 2012 at 11:57 pm

Martyn

A serious question. Would you say this Energy Fair report is a decent piece of analysis compared with the work of David MacKay?

My view is that is incredibly sloppy compared to the rigorous methods used by MacKay. If you believe Energy Fair’s report is good work, then the chances of us getting anywhere here are non-existent.

That is not answering the question. Did Energy Fair make it clear the PNAS study was global? Did they quote a different paper for UK potential?

Robert Wilson9 March 2012 at 12:59 am

Martyn

You continually accuse me of saying things I did not say. I asked why they quoted the global figure when the UK numbers are in the paper. I admit the wording may not have been clear enough. So, I will repeat the question.

Why does Energy Fair tell us global onshore wind potential is 40 times global electricity demand, when they could have said UK onshore potential is 10 times UK electricity demand?

The numbers are in the paper, so there is no justification to not use the UK figures in the context of a report arguing against nuclear in the UK.

And can you also justify your approval of the proposition that 100% onshore wind is a ‘piece of piss’, assuming the PNAS numbers are accurate.

I have outlined earlier why I would disagree with that statement and I would prefer you to prove me wrong than insult me.

martyn9 March 2012 at 1:05 am

I am asking you two questions. Do energy fair make it clear the PNAS figure is global? And do they cite a different paper for UK potential? Why won’t you answer those simple questions?

Robert Wilson9 March 2012 at 2:03 am

Martyn

Please stop accusing me of saying things I make clear I did not say. If I say I am not accusing Energy Fair of not stating something then why repeat the question? My criticism is that a global figure is of small relevance to the UK debate, so why do they mention this number. We can argue over whether the quote could be misunderstood, but that will take us nowhere.

Also, I did not accuse them of not reporting a UK figure. However can you please point out where in the report the UK figures are? One of the bullet point mentions European potential but not UK. Is the number somewhere else in the report?

The European numbers are also wildly optimistic. I have never come across anyone who believes it is possible for offshore wind to provide 60% of Europe’s electricity demand by 2020, yet Energy Fair make it seem as if this may be a realistic option.

Robert Wilson9 March 2012 at 12:21 am

Martyn

You also said the PNAS results made getting 100% solar ‘look like a piece of piss’. Can you please explain how this statement is justified? And I would prefer an answer, not an insult.

Earlier I explained why I thought 100% onshore wind is unrealistic, and I would like you to explain why it is a ‘piece of piss’.

I have no idea where this latest response is coming from. I am criticizing how they used the PNAS paper, not the fact that they used it. Please address those criticisms and also tell me where in the Energy Fair report the UK onshore wind figures are stated. I am not saying they are not there, but have only found global and Europe figures.

“I am not entirely sure if the authors of the report read the PNAS paper and did not understand it or if they did understand it but simply assumed they could quote mine from it and get away with it.”

They quoted the report perfectly fully, they added other reports that put it in context, they loinked those reports and they allowed people to draw their own conclusions.

You might note that my very first post on this thread said

“I think it is perfectly fair to query whether this”

by which I was referring to the 66% solar figure

“is a useful way to illustrate the potential of renewables or not. Personally I’d say it is a bit like saying we can pay off the deficit by putting £234,632 tax on every packet of fags – possibly true* but not actually very helpful”

This falls short of you claiming that the figures are of no relevance – they are the starting point for looking at renewable energy capacity (which is why David Mackay uses a similar approach) but they are only the starting point.

My objection to your posts is not your opinion of the Energy Fair report but your unjustified accusations that they are misleading people. This builds on the overall thrust of the thread – asking a question about 100% solar power for the UK which no one is calling for. It also builds on Mark Lynas’s extraction of one of seven bullet points without any context.

If there is quote mining going on it is there – just as it would be if I wrote a column headed

“Could fast breeder with ocean extraction of uranium power the UK?”

and then quoted David Mackay saying

“If fast reactors are 60 times more efficient, the same extraction of ocean
uranium could deliver 420 kWh per day per person. At last, a sustainable
figure that beats current consumption!”

He is not proposing that, Energy Fair are not proposing 66% solar power.

You have said here that the criticisms Mark and I have made of Energy Fair are unjustified. Mark initially laid out clearly why he thought the Energy Fair solar numbers were highly unrealistic. You may disagree with him on the justification, but please do not say he did not give a justification.

I have also pointed out with full reference to the original PNAS paper why the “4,000%” figure is misleading. Energy Fair is basically saying “if we are covered all available land with wind turbines we would get more than enough energy, so we don’t need nuclear”. I have given my explanation for why if you put a realistic figure for land used for wind farms this 4,000% figure gets a hell of a lot smaller. You have at no point addressed this criticism, instead have thrown around accusations that I have said this and that about Energy Fair’s report, when I said none of these things.

And also, I have twice asked you to point to where the UK figures are in the report. You repeated your implication that I said there was no UK figure, despite me never claiming this. I cannot see one, though it may be there. If you cannot show where this figure, please retract your earlier implication and also explain why you were asking me if it was there.

I must also say that your claim David MacKay uses the “same approach” as Energy Fair is unfair to MacKay. He wrote Sustainable Energy Without The Hot Air mainly to deal with groups throwing around big numbers, and I would be very surprising if he didn’t disapprove of what is in the Energy Fair report.

“I must also say that your claim David MacKay uses the “same approach” as Energy Fair is unfair to MacKay.”

I said – with emphasis added now to make it absolutely clear

“they [theoretical capacity of renewables] are the **starting point** for looking at renewable energy capacity (which is why David Mackay uses a similar approach) but they are only the starting point.”

David Mackay does start with exactly that approach in chapter after chapter of his book. He is right to. It is the logical place to start.

I agree that this is logical place to start, but why did Energy Fair start and finish with the figure and not use a realistic one?

Also, I must press on the location of this UK figure. You repeatedly implied I said it was not there, when I never claimed it wasn’t. I am not claiming it isn’t, so don’t start claiming again that I do, but I have not found where this figure is. Please show me where in the report the UK figure is located.

“You have said here that the criticisms Mark and I have made of Energy Fair are unjustified. Mark initially laid out clearly why he thought the Energy Fair solar numbers were highly unrealistic. You may disagree with him on the justification, but please do not say he did not give a justification.”

Neither of you have criticised the figure they gave for being wrong in fact – that of 66% of UK generation if you cover all surfaces with solar panels. I assume we all think that this is at least in the right ball-park.

Both of you have criticised Energy Fair for covering all surfaces in PV panels is not practical. But Energy Fair did not say that it was, or that it should be done. Therefore you are both criticising an argument that no one has made.

Sorry, this is not good enough. You twice implied I was claiming the report did not include a figure for UK onshore wind. When doing this you said it was there. Now, please point me to where in the report this figure is located. I have not found it, but it may be there.

“I agree that this is logical place to start, but why did Energy Fair start and finish with the figure and not use a realistic one?”

That is a perfectly fair question which obviously I cannot answer. You need to ask Energy Fair. Possibly they felt that by showing there were many mulitples of the power we need available from renewables, they did not need to. If that were their thinking, I do not agree with it.

I commented on Mark’s blog because it is the appropriate place to point out errors in *his* writing. And he (and you) are misusing a quote from this report to argue a misleading claim is being made for solar. It is a huge flaw in your position that the claim in question is not being made.

Can you please answer my question about the location of the UK onshore wind figure in the report? You stated that because they had given this figure they were not giving a misleading impression of UK onshore wind potential. Now, I am not saying it is not in the report, but I cannot find it.

We probably should stop debating about this solar/wind issue. Not sure if we are going to convince each other, but in summary my problem with the numbers is that none of them are realistic numbers. If Energy Fair is to argue that we can get our electricity needs purely from renewables then they must use realistic figures. It’s a fundamental requirement as far as I am concerned.

“If Energy Fair is to argue that we can get our electricity needs purely from renewables then they must use realistic figures.”

I agree. That goes for anyone.

It is also irrelevant to the point I have been making – because Mark’s headline implied that people were arguing we can power the UK with solar. Not with all renewables, just solar. As evidence he said that Energy Fair’s 66% figure (despite being 44% short) was unreaslitic and couldn’t be achieved. Which is true – but is not what Energy Fair were arguing for.

“We probably should stop debating about this solar/wind issue.”

In all honesty I am not debating a solar/wind issue. I am debating whether this column accurately (and many of your posts) describes a particular argument before knocking it down. Had Mark written the David Mackay/fast breeder/uranium from the sea column I used as an illustration earlier, would say it was wrong too.

That it is about solar and wind is of no consequence whatever.

Cyril R9 March 2012 at 12:50 pm

If energy fair is arguing for less than 66% solar then it means you can’t power the UK with solar.

It does not matter to me what Energy Fair says. It matters to me that you cannot power the UK with solar, indeed you cannot power it with solar, wind, geothermal, tidal, and biomass combined. For many reasons which are obvious to people who know basic maths, but mostly have to do with when the energy is delivered versus when we need it (conversely, in the cases where this is much less so, such as biomass and hydro, that have storage built-in, the problem becomes that we don’t have enough of these energy sources).

martyn9 March 2012 at 12:54 pm

“If energy fair is arguing for less than 66% solar then it means you can’t power the UK with solar.”

Clearly sir, you are a genius.

But the key point is that Energy Fair are not arguing for solar to provide 66% of UK energy. Which is why the whole basis of this column is so flawed.

Cyril R9 March 2012 at 3:34 pm

And you continue to miss the main point. You can’t power the UK with wind and solar and geothermal and hydro and biomass and wave and tidal combined, for reasons given over and over. Not with the best of intentions.

Robert Wilson9 March 2012 at 1:19 pm

Martyn

Why can you not answer my question about the location of the UK onshore wind figures in the report? You were happy to imply I said they were not there, despite me not claiming this. These numbers may be in the report, and I am happy for your to point me in the correct direction.

You made it clear that you thought my criticism of them quoting a global figure was irrelevant due to them also reporting a UK figure. If the figures are not quoted in the report then your argument is completely undermined.

martyn9 March 2012 at 1:37 pm

Robert

With the greatest of respect my argument is not undermined by any number of detailed points contained in the report. It is much more fuindamental than that because it says the whole basis on which yours and Mark’s arguments are made is completely flawed.

This article asks the question

“Can solar power the UK?”

It explains that question needs to be asked because it alleges solar advocates make sweeping and unrealistic claims about what can be achieved with solar power in the UK.

It then cherrypicks one statement as an example, and seeks to argue that it does not stand up to serious scrutiny. It does not do this by showing that it is factually wrong – that covering all surfaces with PV would not generate 266TWh of power – but by saying it is not practical to cover all those surfaces. Given that nowhere in the report the statement was taken from did the authors argue doing such a thing was practical, the fundamental basis of the argument completely falls apart.

In your comments you have largely repeated this flawed process, but using another bullet point from the report, this time on wind.

Until you accept that, I cannot really see the point in going back over old ground over and over again.

Robert Wilson9 March 2012 at 1:51 pm

Martyn

Sorry, answering the question is fairly straightforward. You have thrown words such as cherrypicking and misleading around pretty casually here.

Now, it seems simple to me. The Energy Fair report does not appear to show UK onshore wind figures, and if they do you will not show me where. They quote global figures from the PNAS report. The PNAS report gives estimates for the UK that are 4 times lower than the global, yet Energy Fair decided not to report the UK figures. If you don’t think this is misleading or an example of cherrypicking, then you don’t know the meaning of the words.

If I walked around the scientists here and asked their opinion of this, they would say it is textbook cherrypicking. You on the other hand think I am the one doing the cherrypicking.

I have been debating this article with you for 3 days now and you will not accept that it is entirely based on a fallacious argument – because Energy Fair did not say that covering all surfaces in solar panels was practical.

For 3 days we have been round the houses through this report and that – on my part because I am attempting to use other points to illustrate this fundamental error. It was in doing that I first raised the bullet point that referenced global wind potential.

But whenever I try to illustrate a point in this way you get bogged down in detail around it when actually it is the basis of the article I object to. Even worse when I pointed out that another bullet point had a technical potential for global wind, you actually simply repeated the fundamental error Mark had made in his solar argument, but now on the wind point instead.

If I cannot convince you to examine the fundamental basis of the article critically after 3 days, then I am no longer going to introduce other, less important illustrations and examples which we then have to go over exhaustively. Instead I will stick to the main point.

I accept there is a risk that this may not work – but after 3 days of doing it a different way, I am going to give this a try. I think that is reasonable.

The two of us have had more or less no discussion about solar, but mostly talked about their wind figures. During this discussion I accused them of cherrypicking high wind figures, however you said they were not doing this because they included UK figures somewhere else in the report.

You have clearly accused me of being misleading about what Energy Fair reported about wind, along with calling me a cherrypicker. It is completely unacceptable to go around making these claims on the basis that I was ignoring that Energy Fair had reported UK onshore wind figures elsewhere. Either point me in the direction of these UK wind figures or explain how you can go around claiming I am misleading and a cherrypicker.

I also backed up my argument that the Energy Fair numbers were misleading by making clear reference to the original PNAS figures, however you appear to believe calling me names is a good response to any question.

You began by saying Mark’s question about solar was “valid”. You have not written anything that indicates a change of mind.

In fact you followed this up by saying “The criticism is that they claimed the UK could aim for 66%”. Which is not true.

You also said “Mark initially laid out clearly why he thought the Energy Fair solar numbers were highly unrealistic”. It is of course true that Mark did do that, but you again ignore the fact that Energy Fair had not said they were realistic in the first place.

So this article about solar has a huge flaw at its heart, and we have debated it. It is based on a false premise that Energy Fair said 66% solar was realistic. They did not. You cannot show they did, but will not accept they didn’t.

You really are a lawyer. Typical lawyer science, this person says this, but my client didn’t say that, blah blah. At the same time you have very poor knowledge of factual content.

You have utterly failed in rebutting the main argument, which is that you cannot power the UK on renewables. Not on solar, not on some rediculous mix of wind, solar, hydro, wave and whatever else matches your fancy.

Robert Wilson9 March 2012 at 2:51 pm

Martyn

I really need an answer on this. I have no idea about the ethical standards where you work, but in science if you accuse someone of cherrypicking you are normally expected to back it up with evidence.

I have explained repeatedly why I think Energy Fair cherrypicked from the PNAS report, and am completely willing to defend that accusation. You on the other hand have accused me of cherrypicking on the basis of the report including a figure for UK onshore wind, which you cannot point me to the location of.

Either provide this source or explain to me why Energy Fair using the global figure from the report instead of the lower UK figure is not an example of cherrypicking.

This will be a lot quicker if you will answer my question. I am calling your honesty into question and your response is to not answer the question. You stated the report had UK figures, and accused me of cherrypicking on that basis. Please point to these figures. If you can do this then I am happy to say you were not being dishonest.

I will accept that you accused Mark Lynas and not me of cherry picking.

However, that response simply will not do. You accused me of being misleading about the Energy Fair’s onshore wind claims, and of ignoring other parts of the report. Now, why can you not point me in the direction of these figures? You seem to be implying that it is a trivial issue. If you really believe this was a trivial issue then you would have answered the question long ago.

Now come on, answer the question. Either the UK onshore figures are in the report or they are not, and as I say I am unable to find them, but may have missed them.

I am now giving up on this debate as it is going nowhere, but will make a final statement.

The Energy Fair report is a shoddy piece of work from beginning to end. I am sad to see that there are some very prominent people in the environmental movement who have been willing to have their name attached to it, but that’s the way it is. Going through the details of the report has greatly increased my pessimism about the state of environmentalism in the UK. We can decide to base our energy policy decisions on work by the likes of David MacKay or the Committee on Climate Change, or we can use reports such as Energy Fair’s. If we choose the latter we are setting ourselves up for failure.

The headline is “Can Solar PV really power the UK?” You have questioned whether this headline is justified, given that no one is arguing for 100% solar, and the article does not address claims of 100% solar.

Frankly I don’t care much about headlines, and routinely feel like punching the Guardian’s sub-editors. However, I will agree that Mark’s choice of words may have not been wise. Based on his article a better summary of he is arguing would be “Can Solar PV provide the majority of the UK’s electricity?” Not as snappy as the original certainly. However, I believe it is much more important to discuss what is in the article, instead of having a debate over whether Mark is a good headline writer.

I agree that Energy Fair are not proposing 66% wind. However, Mark has at no point claimed they did. Their claim was that 66% is practicable. Mark has expressed the view that it is not practicable, and has stated with references what his view is of realistic figures. I don’t see whether or not they proposed this as being relevant to what Mark has written.

I will say that Mark may not have been on to a good thing quoting from Energy Fair in this article. From my earlier statements you probably know my views on Energy Fair, and I certainly don’t disapprove of Mark calling them a “solar front group”. However, it may been better to focus on a statement from someone like Jeremy Leggett. I recognise there are many anti-nuclear environmentalists who would have been put off by the Energy Fair references. Plus Leggett has made statements in the past that would have allowed Mark to use his “Can the UK really be powered by solar?” headline without anyone complaining.

Finally, I think it is important that Mark has raised this question of the amount of solar we can realistically get. There needs to be a serious debate in the UK about which forms of renewables are best, and this debate is simply not happening. We need to compare our options and choose winners, and preferably do this quickly.

As I say I do not intend to post anything more, but will now be sitting at 99 comments, and it would be a shame for it to end there.

I am glad you posted once more – in my opinion it is the best post you have made. I do not agree with every word of it, but its thrust is in the right area.

While your peppers headline on majority of power from solar is an improvement it still is not justified by what EF said. Nor is your claim that EF said 66% is practicable, their report does not make that claim.

Similarly you say that Jeremy Leggett would have been a better target – but the last time you quoted him you didn’t choose a quote that justified that either.

The weakness of the EF report is that it does not say what is practicable. I have said this in earlier posts. But while that is a weakness, it does not justify misrepresnting selected sentences of their report to criticise them. Criticising the gap is something I would not have argued against.

You may think I am nitpicking, and I understand your cynicism about headlines. So let me explain why it matters.

In important areas of climate policy, Mark, George Monbiot, David Mackay and others have carved out a useful niche in policy analysis. As a shorthand I will call it climate policy pragmatism – not a term I like because I think there are pragmatic considerations they ignore, but I will use it because I think that pragmatism is a sensible aim and is what drives them. My impression is you have much sympathy with this strand of green thinking. It may surprise you to hear that I do too.

However, in part this strand of green thinking has defined itself by opposing the “purer” green thinking of the traditional sandal clad idealist. Please forgive me for not defining that to the nth degree – I hope you know what I mean.

Now I have no problem with this when it is really taking on daft things traditional greens have said. But as someone who worked for many years in the “traditional” green sector I spent a large proportion of my time explaining that the positions people ascribed to us were not our position.

The myths of what Friends of the Earth wanted were of course in large part built up by opponents – politicians and pressure groups who did not want CO2 emissions tackled. But those people also leapt on any “friendly fire” as especially potent evidence we were nuts. You will have seen how Monbiot is quoted on FITs for example.

Now if the criticism is valid I can cope with this – that shows the traditional greens should get their act together. But I am very sensitive to headlines about, for example, 100% solar power that build the perception greens are basically mad but are misrrprentations of what they are actually proposing.

So I think Mark and others have a duty to hold traditional greens to account without fear or favour – that is good. But they also must do it honestly and with full recognition of the power their views have because of the way they are amplified by those who really do not want action taken.

This blog fell short – I am glad you finally agreed at least in part. I hope Mark will reflect to and not stop criticising Energy Fair etc, but will do it less lazily and by addressing what they actually said, rather than propagating myths about greens by posing questions on things they did not say.

I too will now drop this – I hope we have reached a better understanding of each others points of view even if not 100% agreement. I would be interested in your views on the reasons behind me pursuing this even if we drop the actual content from here on in – we have done that to death.

You have raised some very good issues here, so I will make another comment. As you guess I have more in common with those who promote “climate policy pragmatism” than traditional Green policies. My main approach to the issues is from the scientific, not the activist end. As I have earlier implied I believe one of the greatest problems the green movement currently has is its lack of a critical attitude to renewable energy. I think the environmental movement’s attitude to energy issues would be improved a great deal if they kept in mind the words of the great physicist Richard Feynman: “For a successful technology, reality must take precedence over public relations, for nature cannot be fooled.” I think you will agree that a belief environmentalists take an uncritical attitude to renewables is something Mark, George Monbiot and David MacKay share. The attitude of environmentalists is currently a big problem, but I agree with you that people need to be responsible when considering the tone of their writing.

It is clear that both Mark and George Monbiot believe the environmental movement is currently in a poor condition. (I will let you decide if “poor” is the word they would choose). A good example of this would be Monbiot’s statement that Green opposition to nuclear in the last year has “done more harm to the environment than climate skeptics have ever achived” (http://www.monbiot.com/2011/12/05/a-waste-of-waste/). Support for nuclear is the issue that most unites the “pragmatist” movement, and it is the key issue that is pushing some people away from what you have called traditional Green thinking, so I believe it would be better if I mostly considered this issue from here on.

Those on the pro-nuclear side of the debate face a very difficult question, whether the Green movement is now part of the problem, not the solution, and if so should they be opposed. The statements made by Mark and George Monbiot about the recent actions by The Green Party and Greenpeace have displayed an element of disdain, but I believe so far neither have moved into a position of outright opposition. However, if the pragmatists move fully to a position where they believe climate cannot be fixed without nuclear, then they will likely have no choice but to fight a war on both fronts against climate skeptics, and anti-nuclear Greens. Right now things are in the balance, and as a result it is very difficult for people such as George Monbiot to choose the correct tone. However, pessimism about the traditional environmental movement may very quickly change to opposition to it.

So, returning to the key issue you raise, should Mark or George Monbiot be sensitive about whether what they write can be misused by the opponents of traditional Green groups? The answer is yes and no, depending on just how pessmisitic either of them are about the current condition of the traditional Green movement. Is Greenpeace, for example, now a net-negative in the fight against climate change? My interpretation of what Mark has written on the issue is that he believes they are. If this is the case it is perhaps unfair to expect Mark to be sensitive about his comments being used against Greenpeace. If however, Mark or George Monbiot believe that the Green movement is not yet a net-negative on the environment, or are optimistic about the movement turning a corner, then they should be very careful that their words cannot be used to discredit these groups more generally.

The final related, and perhaps most difficult question, is whether pragmatists should break completely from the Green movement. I am a scientist, and prepare to think, not do, so my views on this are probably not worth a damn. However, this may be the best direction to take. If you were to consider the more controversial aspects of The God Species. Within the Green movement these views are heretical, yet outside it they are from from controversial. Take agriculture. The current Green consensus is for organic agriculture. Mark offers the contrarian view, which I share, that organic agriculture is worse for biodiversity than conventional agriculture. Despite being a view that would shock many Greens to their core, it is one that is very mainstream among conservation scientists, with recent papers in prestigious journals providing evidence for this viewpoint. The same is true for nuclear and GM. There is clear political/scientific support for both. Aiming everything what we write on these issues towards Greens may be counter productive. Most people don’t consider the views of the Green Party when they think about nuclear power, so is it necessary to attack them by default? Personally I do not know the answer. It is clear we need strong and not weak action on a lot of issues, and so polarization may be a necessity. The difficulty with polarization is that we end up with only one policy, and it may not be the policy we want.

Thank you for your insightful comment. I believe you have articulated very well certain conundrums and tensions as they exist at this point in time. By short introduction, I am a lifelong environmentalist and advocate with the economic and professional scars to prove it. I “switched” from anti-nuclear to pro-nuclear after a couple of years of independent re-study of the issue, in light of environmental and human development values, in the the early 2000’s.

Objectively, institutional environmentalists seem to prefer climate change to nuclear energy. They seem willing to let runaway climate change drastically change this planet, so long as they can retain their accustomed anti-nuclear stance.

In the face of the demonstrated (with careful numbers) inability of their preferred solutions to scale up in a reasonable time frame and at a cost that decision makers and societies will deem bearable, they have maintained a stubborn and unreasoned unwillingness to fairly consider today’s existing and developing nuclear technologies against their competitors in light of the values environmentalists claim to possess. Their response to the potential offered by advanced nuclear – – a young technology (I note that 2012 is only 70 years past Fermi’s atomic pile at the University of Chicago) is, resultantly, primarily rhetorical and political, instead of rational and reasoned.

In the U.S., institutional environmentalists long aligned themselves with gas interests. Recent EPA study has confirmed what had already been researched and written about earlier, i.e., that “natural” gas (due to methane leaks in fields and through the system) has about the same greenhouse impacts as coal.

In the short term – – which seems to matter more and more, with things getting worse quickly – – natural gas’s impacts may well be worse than coal because of the short term potency of methane as a GHG. The Sierra Club accepted $26 million from a gas Company for its (credit where credit is due – skillfully pursued) campaign against new coal fired plants. An unfortunate consequence of the long alliance has been to vastly increase the political and economic power of a fossil fuel interest, the gas Companies. You will find those Companies quite friendly, in their public relations, toward renewables. They know the renewables/conservation/efficiency paradigm does not challenge their market position.

Advanced nuclear can.

I believe institutional environmentalists aligned themselves with gas interests because they consider nuclear, a priori, anathema – – utterly unacceptable, no questions asked. Gas, it is often said “works well with renewables.”

So, gas is accepted and promoted (or has been). For an institution, is very difficult to change a long-held position.

Knee-jerk anti-nuclear views have, in the face of all evidence – – e.g., the benchmark numbers on climate keep generally accelerating in the wrong direction, and apparent symptoms become more pronounced – – to cling to a technological prescription has failed to demonstrate viability at the scale needed, irrespective of massive efforts and investment.

Against the weight of the evidence, institutional environmentalists cling to the hope that technological advances in their preferred technologies will solve the inherent deficiencies of their preferred energy sources. Supporting such hopes, analysts in or around that community have endlessly predicted utopia is just around the corner:

The statement criticized by Mark Lynas is in about the same vein as some of these other exciting, meaningless and ultimately misleading projections. Expectations of an imminent renewable energy paradise are endlessly flogged in the environmentalist echo chamber, creating the impression, among committed and well-intentioned followers, that nuclear is, at best, a “distraction.”

To those who believe (in the reigning theoretical energy paradigm of institutional environmentalists) no reason is necessary. To those who do not believe (that advanced nuclear has something to offer) no reason is sufficient.

At a time when careful reasoning is needed among environmentalists, this entrenched system of belief and disbelief is a problem.

Fluffing renewable energy potential is misleading. It creates an overall impression that something is quite feasible when it is quite not. This was, I think, the underlying point of Mark Lynas’s article, and it is one that has to be made forcefully, again and again.

Hopefully, environmental institutions will find a way to change their position. In the meantime, no-apologies advocacy of advanced nuclear energy as an energy and emissions strategy, within a framework of regulation in the public interest, must come from others with the independence and courage to do so.

I believe that this is what Mark Lynas does, and George Monbiot have recognized and acted upon. They have proceeded forward irrespective of the attacks and accusations that arise as a consequence. It is also what you have done. Good work. Thanks.

I just would like to articulate my appreciation for the discussion here. it’s excellent and informative.

I especially appreciate Cyril’s efforts. and the civility between Martyn and Cyril (I have not read everything yet but so far so good).

I recently checked the prices of cheap solar systems, and the lowest price I found on the net for a 920 KW system was 3500 dollars, down from 4000. and this did not include batteries. so it makes me wonder about chris goodall’s numbers. The panels are coming down in price for sure. but the key point is that arguments around solar grid parity don’t make much sense since as Cyril indicates 10 cents per kwh for solar is not equal to 10 cents per kwh for a basepower source.

Oh: I would also note that I am really depressed by the 100% renewables argument that points to a particular point in time where renewables were performing well as if this particular point in time can be generalized.

Bill Mckibben has done this numerous times, highlighting really good minutes of the day in the summer when germany PVs were just cranking it out.

and more scholarly types like mark jacobsen do it too: modeling how california during a period in july could mix and match renewables for a perfect fit. the assumption is (and I would not take the modeling at face value) that this situation can be generalized and scaled. and that’s the problem.

Living in Florida makes one think of solar power. Rooftop solar is a no brainer here as long as you can get the absurdly generous grants offered by Florida Power & Light and Progress Energy. The only thing stopping me from installing a 5 kW system is my wife who insists that the granite counter tops come first.